<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_JS的三种引入方式</title>
</head>
<body>
<button onclick="alert('请先登录！')">点击即玩</button>
<button onclick="console.log('赛博木鱼')">点击即玩</button>

<h1 id="aaa">我是一级标题</h1>

<script>
    console.log('我是内部JS代码')
    console.log(aaa)
</script>

<script src="01.js">
    console.log('引入外部代码时，内部不执行')
</script>
</body>
</html>